• Alert level at Clevelandraised as a new lava dome becomes evident
• A significant increase in seismicity at Nevado del Ruiz brings a rise in the alert level
• High levels of sulphur dioxide emissions at Soufrière Hills
• Another paroxysmal eruptive episode at Etna with lava fountaining and ashfall

Click on the map for a larger version (1211 x 784 pixels).

The Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report for 28 March to 3 April 2012 is now available on the Global Volcanism Program website. The following is a summary and not a substitute for the full report.

• The current report: Weekly Volcanic Activity Report.
• Previous reports: Weekly Reports Archive.
• The SI/USGS map of volcanoes discussed this week.

New activity/unrest: Cleveland (Alaska, USA), Fuego (Guatemala), Iliamna (Alaska, USA), Lewotobi (Indonesia), Nevado del Ruiz (Colombia), Soufrière Hills (Montserrat), Sundoro (Indonesia).

Ongoing activity: Etna (Italy), Karymsky (Russia), Kilauea (Hawaii, USA), Popocatépetl (Mexico), Puyehue-Cordón Caulle (Chile), Shiveluch (Russia), Tengger Caldera (Indonesia), Tungurahua (Ecuador).

Note: ‘a.s.l.’ = ‘above sea level’.

NEW ACTIVITY/UNREST

Cleveland (Alaska, USA). AVO reported that on 28 March the Volcano Alert Level for Cleveland was raised to Watch and the Aviation Color Code was raised to Orange due to the formation of a new lava dome, observed in satellite imagery, which extruded in the summit crater during the previous week. During 29 March-3 April cloud cover prevented observations of the crater. Elevated surface temperatures consistent with a hot lava dome were detected in infrared satellite imagery on 4 April. No seismic information was available because Cleveland does not have a real-time seismic network. [GVP: Cleveland]

Fuego (Guatemala). INSIVUMEH reported that during 31 March-1 April and 3-4 April explosions from Fuego produced ash plumes that rose 500-800 m above the crater and drifted 10 km W and NW. During the night lava fountains rose 100-150 m above the crater and formed avalanches that traveled towards the Río Cenizas drainage. Based on analysis of satellite imagery, the Washington VAAC reported that on 1 April an ash plume drifted 13 km WSW and a well-defined thermal anomaly was observed. [GVP: Fuego]

Iliamna (Alaska, USA). AVO reported that during 28 March-3 April seismicity at Iliamna remained above background levels, although just slightly, during 25-27 March. When not obscured by clouds, satellite and web camera views showed nothing unusual. The Alert Level remained at Advisory and the Aviation Color Code remained at Yellow. [GVP: Iliamna]

Lewotobi (Indonesia). CVGHM reported that seismicity at Lewotobi Lakilaki, one of two stratovolcanoes comprising Lewotobi, fluctuated but declined overall during 18 September 2011-25 March 2012. No significant changes were observed at the volcano. The Alert Level was lowered to 1 (on a scale of 1-4) on 29 March. Observers of Lewotobi Perempuan, the second stratovolcano comprising Lewotobi, noted that during January-March diffuse white plumes rose 15 m above the crater and no significant changes had occurred. After 31 August 2011 through 25 March 2012 seismicity fluctuated but declined overall. On 29 March the Alert Level was lowered to 1. [GVP: Lewotobi]

Nevado del Ruiz (Colombia). According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 24-31 March seismicity at Nevado del Ruiz increased significantly. Earthquakes indicating rock fracturing occurred W of Arenas crater, exhibiting a pattern observed prior to the eruptions in 1985 and 1989, although less energetic. Starting at 1054 on 29 March, and lasting for about 25 minutes, more than 135 earthquakes were detected S of Arenas crater at a depth of 4 km. At 0400 on 31 March earthquake signals indicating rock fracturing and fluid movement markedly increased. The Alert Level was raised to II (Orange; “eruption likely within days or weeks”). Seismicity remained elevated during 1-3 April; earthquakes were located below Arenas crater at depths between 0.5 and 3 km. [GVP: Nevado del Ruiz]

Soufrière Hills (Montserrat). MVO reported that during 24-30 March activity at the Soufrière Hills lava dome was generally at a low level and no ash-venting episodes had been detected since 23 March. The average sulfur dioxide emission rate measured during the week was 1,320 tonnes per day with a minimum of 264 and a maximum of 4,594, which was the third-highest value recorded in the last ten years. High values occurred between 24 and 26 March, averaging 2,550 tonnes per day over the three days. The average for the rest of the week was around 400 tonnes per day. The Hazard Level remained at 2. [GVP: Soufrière Hills]

Sundoro (Indonesia). CVGHM reported that seismicity at Sundoro continued to increase into January after the Alert Level was raised from 1 to 2 (on a scale of 1-4) on 5 December 2011. After the first week of January through 27 March the number of daily earthquakes significantly decreased. The Alert Level was lowered to 1 on 30 March. [GVP: Sundoro]

ONGOING ACTIVITY

Etna (Italy). Sezione di Catania – Osservatorio Etneo reported that the twenty-third paroxysmal eruptive episode since January 2011 took place at New SE Crater (New SEC) of Etna during the morning of 1 April following two weeks of quiescence. The episode was characterized by tall lava fountains from vents within the crater and on the SE flank of its cone, a gas-and-tephra plume, and lava flows descending toward the Valle del Bove. The paroxysmal phase lasted about 1.5 hours and ended just before daybreak. Ash and lapilli fell over the SE sector of the volcano, affecting mainly the area between Monterosso and Zafferana Etnea, but also the area between Acireale and Giarre, further downslope. [GVP: Etna]

Karymsky (Russia). KVERT reported that during 23-30 March seismic activity from Karymsky continued to be detected, and indicated that possible ash plumes rose to an altitude of 2.5 km (8,200 ft) a.s.l. during 22-26 March. Satellite imagery showed a thermal anomaly on the volcano almost daily. The Aviation Color Code remained at Orange. [GVP: Karymsky]

Kilauea (Hawaii, USA). During 28 March-3 April HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea’s Halema’uma’u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash nearby. Incandescence was visible from both a small pit on the NE edge and a small spatter cone on the SE edge of the Pu’u ‘O’o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, reaching about 1.6 km from the coast. On 2 April a small lava flow issued from a vent on the S edge of the Pu’u ‘O’o crater floor. [GVP: Karymsky]

Popocatépetl (Mexico). CENAPRED reported that during 27 March-3 April steam-and-gas emissions rose from Popocatépetl. Emissions contained small amounts of ash on 28 and 30 March and crater incandescence was observed at night during 31 March-3 April. [GVP: Popocatépetl]

Puyehue-Cordón Caulle (Chile). OVDAS-SERNAGEOMIN reported that during 27 March-3 April satellite and web camera observations of the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, showed plumes that rose no higher than 1.2 km above the crater. Incandescence from the crater was observed every night. The Alert Level remained at Orange. [GVP: Puyehue-Cordón Caulle]

Shiveluch (Russia). KVERT reported that explosive activity at Shiveluch continued during 23-30 March. Ground-based observers and satellite imagery indicated that a viscous lava flow continued to effuse in the crater formed during a 2010 eruption. During 25-26 and 28 March ash plumes rose to an altitude of 7 km (23,000 ft) a.s.l. Satellite imagery showed a weak thermal anomaly daily on the volcano and ash plumes that drifted 192 km E and SE during 25-28 March. The Aviation Color Code remained at Orange. [GVP: Shiveluch]

Tengger Caldera (Indonesia). CVGHM reported that during 1 January-29 March white plumes from Tengger Caldera’s Bromo cone rose 50 m above the crater and seismicity declined. On 30 March the Alert Level was lowered to 1 (on a scale of 1-4). [GVP: Tengger Caldera]

Tungurahua (Ecuador). IG reported that during 28 March-3 April visual observations of Tungurahua were mostly limited due to cloud cover. A plume rose 800 m above the crater on 1 April and ashfall was reported in Pillate (7 km W), Choglontus (13 km WSW), and Motilones (W). Lahars descended the Pingullo and Achupashal (NW) drainages, carrying material 30 cm in diameter and causing a temporary road closure. [GVP: Tungurahua]

The foregoing is a summary of the Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report covering 28 March to 3 April 2012. It is provided for information only, and is based on but not a substitute for the full report, which comes with its own criteria and disclaimers. The map base is derived from the Smithsonian Institution/USGS/US Naval Research Laboratory This Dynamic Planet website.

For all our coverage of the SI/USGS Weekly Volcanic Activity Reports: Weekly Volcanic Activity Reports « The Volcanism Blog.

* The other possibility, of course, is that I did something wrong. If it was a glitch, I should say that it really hardly ever happens, and I am very happy with WordPress as a rule.

• A plume, probably water vapour, seen from Iliamna, where seismicity remained elevated
• Seismicity decreased at Nevado del Ruiz but significant gas emissions continued
• Etna continued lively with lava flows and fountaining, and strong ash emission
• Daily explosions at Shiveluch produced plumes which reached 3-5 km altitude

Click on the map for a larger version (1211 x 784 pixels).

The Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report for 14-20 March 2012 is now available on the Global Volcanism Program website. The following is a summary and not a substitute for the full report.

• The current report: Weekly Volcanic Activity Report.
• Previous reports: Weekly Reports Archive.
• The SI/USGS map of volcanoes discussed this week.

New activity/unrest: Iliamna (Alaska, USA), Nevado del Ruiz (Colombia).

Ongoing activity: Cleveland (Alaska, USA), Etna (Italy), Karymsky (Russia), Kilauea (Hawaii, USA), Kizimen (Russia), Popocatépetl (Mexico, Puyehue-Cordón Caulle (Chile), Sakura-jima (Japan), Shiveluch (Russia), Soufrière Hills (Montserrat), Tungurahua (Ecuador), Villarrica (Chile).

Note: ‘a.s.l.’ = ‘above sea level’.

NEW ACTIVITY/UNREST

Iliamna (Alaska, USA). AVO reported that during 9-20 March seismicity at Iliamna was above background levels. Satellite images acquired during 9-16 March showed a plume drifting 56 km downwind that was likely water vapor. The report noted that long-lived fumaroles at the summit of Iliamna frequently produced visible plumes, but the current plume appeared to be more robust than usual. Scientists aboard an overflight on 17 March observed vigorous and plentiful fumaroles at the summit, consistent with the elevated gas emissions. Gas measurements indicated that the volcano was emitting elevated levels of sulphur dioxide and carbon dioxide. The Alert Level remained at Advisory and the Aviation Colour Code remained at Yellow. [GVP: Iliamna]

Nevado del Ruiz, (Colombia). According to INGEOMINAS, the Observatorio Vulcanológico and Sismológico de Manizales reported that during 12-18 March seismicity at Nevado del Ruiz decreased but gas emissions remained at significant levels. Gas plumes rose 2 km above the crater and sulphur dioxide odors were reported by local people. The Alert Level remained at III (Yellow; ‘changes in the behaviour of volcanic activity’). [GVP: Nevado del Ruiz]

ONGOING ACTIVITY

Cleveland (Alaska, USA). AVO reported that a small explosion from Cleveland was detected at 1455 on 13 March by distant seismic stations and infrasound arrays. Weather conditions prevented the detection of a possible eruption cloud in satellite images or by visual observation of the summit. No other activity was detected during 14-19 March. The Volcano Alert Level remained at Watch and the Aviation Colour Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network. [GVP: Cleveland]

Etna (Italy). Sezione di Catania – Osservatorio Etneo reported that the twenty-second paroxysmal eruptive episode since January 2011 took place at New SE Crater (New SEC) of Etna during the morning of 18 March following two weeks of quiescence. Roaring from high-pressure degassing was heard on 16 March. The next day there was incandescence and multiple vapour clouds with minor ash content that rose from New SE Crater. In the early hours of 18 March the incandescence intensified due to Strombolian activity on the crater floor, and volcanic tremor amplitude rapidly increased. Strombolian activity continued to intensify, and just before 0700 lava flowed through the deep breach in the SE crater rim. At about 0825 the ash content in the gas plume rising from the crater became more significant and pulsating lava fountains from a vent on the crater floor rose about 100 m high. Shortly before 0900 two vents were active within the crater and a jet of lava was emitted from another vent within the breach in the SE crater rim. During 0900-0915 lava fountaining was essentially continuous from all three vents. An intense shower of coarse-grained pyroclastic material falling onto the N and NE flanks of the cone generated avalanches and clouds of rock and dust, which traveled to the base of the cone. A plume rose 4-5 km above Etna and drifted E. Ash and lapilli fell mainly in the area between the villages of Zafferana Etnea and Sant’Alfio, extending toward the Ionian Sea between Riposto and Pozzillo. The main lava flow descended the steep W slope of the Valle del Bove. Several lava lobes, however, took a more northerly path to areas covered with thick snow. The interaction of the lava and snow led to rapid melting of the snow, generating small lahars, and strong explosions that produced ground-hugging vapour-and-ash clouds resembling pyroclastic flows, which repeatedly descended on the floor of the Valle del Bove. The vapour-and-ash clouds rose 1-1.5 km above the floor of the Valle del Bove. This phenomenon continued intermittently for some time after the cessation of the lava fountaining and ash emission, until about 1130. Lava fountaining and strong ash emission continued without significant variations until about 1040; afterwards the activity rapidly diminished in intensity, and the last ash clouds were observed around 1110. Similar to the previous episodes, the lava that flowed through the breach in the SE crater rim advanced for several hours after the cessation of the paroxysmal activity into the upper part of the Valle del Bove. The lava reached a distance of about 4 km from the source, stagnating S of Monte Centenari. A small lava flow, emitted from a fracture on the N flank of the cone, followed the same path as a flow emitted from the same fracture during the 4 March paroxysm, and traveled a few hundred metres. [GVP: Etna]

Karymsky (Russia). KVERT reported that during 9-16 March seismic activity from Karymsky continued to be detected and indicated that possible ash plumes rose to an altitude of 3.1 km (10,100 ft) a.s.l. on 14 March. Satellite imagery showed a thermal anomaly on the volcano during 10-13 March. The Aviation Colour Code remained at Orange. [GVP: Karymsky]

Kilauea (Hawaii, USA). During 14-20 March, HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea’s Halema’uma’u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence was visible from both a small pit on the NE edge and a small spatter cone on the SE edge of the Pu’u ‘O’o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain, and were about 2 km from the coast. [GVP: Kilauea]

Kizimen (Russia). KVERT reported moderate seismic activity at Kizimen during 9-16 March and a large thermal anomaly that was detected in satellite images. Video and satellite observations indicated both continued effusion of a large lava flow on the E flank and hot avalanches. Strong gas-and-steam activity was observed with the video camera. The Aviation Colour Code remained at Orange. [GVP: Kizimen]

Popocatépetl (Mexico). CENAPRED reported that during 14-20 March steam-and-gas emissions rose from Popocatépetl and incandescence from the crater was observed at night. Emissions contained small amounts of ash on 14 March. On 18 March emissions again contained a small amount of ash and were accompanied by increased incandescence from the crater. [GVP: Popocatépetl]

Puyehue-Cordón Caulle (Chile). Based on seismicity detected during 13-20 March, OVDAS-SERNAGEOMIN reported that the eruption from the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, continued at a low level. Plumes observed during 13-16 March in web camera and satellite images rose 0.4-1.2 km above the crater, and drifted 30 km E on 14 March, 20 km N on 15 March, and 17 km NNE on 19 March. Incandescence from the crater was observed during 13-14 and 16-20 March. The Alert Level remained at Red. [GVP: Puyehue-Cordón Caulle]

Sakura-jima (Japan). JMA reported that on 12 March an explosion from Sakura-jima’s Showa crater ejected tephra that landed as far as 2 km from the crater. Based on information from JMA, the Tokyo VAAC reported that during 14-21 March explosions often produced plumes that rose to altitudes of 1.5-2.7 km (5,000-9,000 ft) a.s.l. and drifted N, NW, and SE. Pilots observed ash plumes during 18-20 March that rose to altitudes of 1.2-4 km (4,000-13,000 ft) a.s.l. and drifted SE and E. [GVP: Sakura-jima]

Shiveluch (Russia). KVERT reported that activity at Shiveluch increased on 10 March and during 10-14 March daily explosions produced ash plumes that rose to altitudes of 3-5 km (10,000-16,400 ft) a.s.l. During 10-16 March ground-based observers and satellite imagery indicated that a viscous lava flow continued to effuse in the crater formed during a 2010 eruption. Satellite imagery showed a thermal anomaly on the volcano and ash plumes that drifted 64 km NE and SE during 10-11 and 13 March. The Aviation Colour Code remained at Orange. Based on information from Yelizovo Airport (UHPP) and satellite images, the Tokyo VAAC reported that an ash plume rose to an altitude of 5.2 km (17,000 ft) a.s.l. and drifted SE. [GVP: Shiveluch]

Soufrière Hills (Montserrat). MVO reported that on 9 March at 1720 a small pyroclastic flow from the Soufrière Hills lava dome traveled about 1.75 km W down Spring Ghaut and produced a small ash cloud that rose 1.2 km and drifted W. During 9-16 March activity was at a low level. The Hazard Level remained at 2. [GVP: Soufrière Hills]

Tungurahua (Ecuador). IG reported that, although visual observations of Tungurahua during 14-20 March were mostly limited due to cloud cover, steam plumes were noted on 18 March which drifted W. On 19 March explosions were detected by the seismic network. During brief periods where the crater was visible, observers noted incandescence emanating from the crater and a few blocks rolling 200 m down the flank. Slight ashfall was reported in Choglontus (8 km SW), Manzano (8 km SW), and Penipe (15 km SW) the next morning. [GVP: Tungurahua]

Villarrica (Chile). According to Projecto Observación Visual Volcán Villarrica (POVI), spattering from Villarrica’s lava lake was visible during 7-9 March. Four small ash emissions were observed during 13-14 March. [GVP: Villarrica]

The foregoing is a summary of the Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report covering 14-20 March 2012. It is provided for information only, and is based on but not a substitute for the full report, which comes with its own criteria and disclaimers. The map base is derived from the Smithsonian Institution/USGS/US Naval Research Laboratory This Dynamic Planet website.

For all our coverage of the SI/USGS Weekly Volcanic Activity Reports: Weekly Volcanic Activity Reports « The Volcanism Blog.

The series will be broadcast in four parts from 9 to 12 July and will combine live reports from Kilauea with segments looking at the phenomenon of volcanism and exploring volcanoes around the world. Professor Iain Stewart (British television’s Mr Geology) and Kate Humble (British television’s Ms Natural History) will do the presenting. According to BBC Two controller Jane Hadlow, ‘Volcano Live will offer BBC Two viewers a rare opportunity to join world-class experts at the forefront of cutting-edge volcanology research. Broadcasting live from the edge of one of the world’s most active volcanoes over four days will offer a completely new and unique way of experiencing this powerful and unpredictable natural phenomenon’.

This is a high-profile project by the BBC which, if it puts the science in the foreground, has the potential to do a great deal for the public understanding of volcanoes and volcanology. Let’s hope it fulfils that potential. Let’s also hope that Kilauea doesn’t decide to end its current long-running eruption before the cameras arrive in July. That would be annoying.

News
BBC Two announces Volcano Live – BBC Two press release, 16 March 2012
BBC Two announces its latest live event series Volcano Live – Televisual, 16 March 2012 (BBC press release recycled)
BBC Two to broadcast live from active volcano – imediamonkey, 16 March 2012 (BBC press release recycled, with added gibberish)

• An explosive eruption at Bezymianny sent ash up to 8 km altitude
• Activity at Nevado del Ruiz marked by explosions, ash emissions and increased seismicity
• Cleveland stirs with small explosive eruptions
• Explosions at Santa María produce localized ashfall

Click on the map for a larger version (1211 x 784 pixels).

The Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report for 7-13 March 2012 is now available on the Global Volcanism Program website. The following is a summary and not a substitute for the full report.

• The current report: Weekly Volcanic Activity Report.
• Previous reports: Weekly Reports Archive.
• The SI/USGS map of volcanoes discussed this week.

New activity/unrest: Bezymianny (Russia), Cleveland (Alaska, USA), Ijen (Indonesia), Iliamna (Alaska, USA), Lamongan (Indonesia), Marapi (Indonesia), Nevado del Ruiz (Colombia), Tungurahua (Ecuador).

Ongoing activity: Karymsky (Russia), Kilauea (Hawaii, USA), Kizimen (Russia), Puyehue-Cordón Caulle (Chile), Sakura-jima (Japan), Santa María (Guatemala), Shiveluch (Russia), Villarrica (Chile).

Note: ‘a.s.l.’ = ‘above sea level’.

NEW ACTIVITY/UNREST

Bezymianny (Russia). KVERT reported that a strong explosive eruption from Bezymianny was detected by seismic instruments on 9 March. Ash plumes rose to altitudes of 3.5-5 km (11,500-16,400 ft) a.s.l. and drifted NE. During the most intense phase of the eruption ash plumes from pyroclastic flows rose to an altitude of 8 km (26,200 ft) a.s.l. Satellite imagery showed the plume drifting 700 km NE. Ashfall was reported in Ust-Kamchatsk Village (120 km ENE). Later that day activity decreased significantly and the Aviation Colour Code was lowered to Orange. During 9-13 March strong gas-and-steam emissions were noted, a viscous lava flow effused onto the lava-dome flank, and a thermal anomaly continued to be detected in satellite imagery. The Aviation Colour Code was lowered to Orange on 14 March. [GVP: Bezymianny]

Cleveland (Alaska, USA). AVO reported that a small explosion from Cleveland was detected at 1905 on 7 March by distant seismic stations and infrasound arrays. Weather conditions prevented the detection of a possible eruption cloud in satellite images or by visual observation of the summit. Another small explosion was detected at 1605 on 9 March and again weather conditions prevented observations. No other activity was detected during 11-13 March. The Volcano Alert Level remained at Watch and the Aviation Colour Code remained at Orange. No current seismic information was available because Cleveland does not have a real-time seismic network. [GVP: Cleveland]

Ijen (Indonesia). CVGHM raised the Alert Level for Ijen from 2 to 3 (on a scale of 1-4) on 12 March because of increased seismicity and visual observations. On 10 March scientists observed some plant damage around the crater lake and a 10-m-wide area of disrupted water on the crater-lake surface. [GVP: Ijen]

Iliamna (Alaska, USA). AVO reported that earthquake activity had steadily increased at Iliamna during the past three months. On 9 March AVO increased the Alert Level to Advisory and the Aviation Colour Code to Yellow. The report noted that the current activity was characterized by numerous earthquakes that had varied in their number and magnitude over the past week. [GVP: Iliamna]

Lamongan (Indonesia). CVGHM reported that during 1 February-9 March diffuse white plumes rose at most 20 m above Lamongan. Seismicity increased on 23 February, then fluctuated in intensity through 7 March. Seismicity increased significantly on 8 March and tremor was recorded continuously the next day. CVGHM raised the Alert Level to 2 (on a scale of 1-4) on 9 March. Residents and tourists were prohibited from going within a 1-km-radius of the active crater. [GVP: Lamongan]

Marapi (Indonesia). According to a news article from 5 March, several eruptions from Marapi produced ash plumes during the previous week. An ash plume rose 1 km above the crater on 4 March and drifted 10 km S. A representative from CVGHM noted that the Alert Level remained at 2 (on a scale of 1-4). [GVP: Marapi]

Nevado del Ruiz (Colombia). INGEOMINAS reported a significant increase in seismicity at Nevado del Ruiz during 5-11 March. On 8 March scientists aboard an overflight observed a gas plume that rose 1.4 km above Arenas crater, originating from multiple emission sources and thermally anomalous areas within the crater. They noted ash deposits on the glacier, near the crater rim and on the E flank, likely from an explosion on 22 February. Later that day a small explosion detected by the seismic network produced an ash emission that was observed with a camera installed in La Piranha (NW). Increased sulphur dioxide emissions were also detected. Fieldwork revealed ash deposits at the headwaters of Gualí River, SW of Arenas crater. [GVP: Nevado del Ruiz]

Tungurahua (Ecuador). IG reported that, although visual observations of Tungurahua during 6-11 March were sometimes limited due to cloud cover, steam plumes were noted on 6 and 8 March, and a gas-and-ash plume that rose 500 m above the crater was observed on 7 March. Slight ashfall was reported in Choglontus (13 km WSW) on 7 March. An ash plume rose 1 km above the crater on 11 March and drifted SE. Lahars descended the Chacauco (NW) and Mapayacu (SW) drainages. The next day seismicity increased and an ash plume rose 2-3 km above the crater that drifted W and SW. During 12-13 March ashfall was reported in Choglontus and Manzano (8 km SW). [GVP: Tungurahua]

ONGOING ACTIVITY

Karymsky (Russia). KVERT reported that during 2-9 March seismic activity from Karymsky continued to be detected and indicated that possible ash plumes rose to an altitude of 3.4 km (11,000 ft) a.s.l. on 3 March. Satellite imagery showed a thermal anomaly on the volcano on 2 March. The Aviation Colour Code remained at Orange. [GVP: Karymsky]

Kilauea (Hawaii, USA). During 7-13 March, HVO reported that the lava lake periodically rose and fell in the deep pit within Kilauea’s Halema’uma’u Crater. Almost daily measurements indicated that the gas plume from the vent continued to deposit variable amounts of ash and fresh spatter nearby. Incandescence was visible from both a small pit on the NE edge and a small spatter cone on the SE edge of the Pu’u ‘O’o crater floor, and on the upper part of the lava-tube system on the E flank. Lava flows continued to advance down the pali and across the coastal plain. On 12 March the leading edge of the flows were 9 km SE of Pu’u ‘O’o and about 2 km from the coast. [GVP: Kilauea]

Kizimen (Russia). KVERT reported moderate seismic activity at Kizimen during 2-9 March and a large thermal anomaly that was detected in satellite images. Video and satellite observations indicated both continued effusion of a large lava flow on the E flank and hot avalanches. The Aviation Colour Code remained at Orange. [GVP: Kizimen]

Puyehue-Cordón Caulle (Chile). Based on seismicity detected during 6-13 March, OVDAS-SERNAGEOMIN reported that the eruption from the Cordón Caulle rift zone, part of the Puyehue-Cordón Caulle volcanic complex, continued at a low level. Plumes observed most days in web camera and satellite images rose 0.3-1.2 km above the crater and drifted 30-50 km NNE, E, and SW. Incandescence from the crater was observed during 5-8 and 10-13 March. The Alert Level remained at Red. [GVP: Puyehue-Cordón Caulle]

Sakura-jima (Japan). Based on information from JMA, the Tokyo VAAC reported that during 7-9 and 11-13 March explosions from Sakura-jima often produced plumes that rose to altitudes of 1.2-2.7 km (4,000-9,000 ft) a.s.l. and drifted E and SE. Pilots observed ash plumes during 9 and 11-13 March that rose to altitudes of 1.8-3 km (6,000-10,000 ft) a.s.l. [GVP: Sakura-jima]

Santa María (Guatemala). INSIVUMEH reported that during 8-9 March explosions from Santa María’s Santiaguito lava-dome complex generated ash plumes that rose 800-1,000 m above the crater and drifted W and SW. Block avalanches descended the SE and NW flanks. Ashfall was reported in the communities of Loma Linda, San Marcos, and Palajunoj. During 11-12 March explosions generated ash plumes that rose 800 m above the crater and drifted 20 km SSW. Ashfall was reported at the observatory, on the El Faro and Patzulin ranches, and in the village of Las Marías. Lava flows continued to produce avalanches. [GVP: Santa María]

Shiveluch (Russia). KVERT reported that seismic activity at Shiveluch was low during 2-9 March. Ground-based observers and satellite imagery indicated that a viscous lava flow continued to effuse in the crater formed during a 2010 eruption. Moderate fumarolic activity at the lava dome was observed during 2 and 5-8 March; cloud cover prevented observations on the other days. Satellite imagery showed a weak thermal anomaly over the lava dome during 3, 5, and 7-8 March. The Aviation Colour Code remained at Orange. Based on information from KVERT, the Tokyo VAAC reported that on 10 March an ash plume rose to an altitude of 5.2 km (17,000 ft) a.s.l. and drifted NE. Yelizovo Airport (UHPP) reported that an ash plume rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted SW. [GVP: Shiveluch]

Villarrica (Chile). According to Projecto Observación Visual Volcán Villarrica (POVI), two small ash emissions from Villarrica occurred on 7 March. Incandescence from the crater was observed from the town of Pucon (16 km N) during 7-8 March. [GVP: Villarrica]

The foregoing is a summary of the Smithsonian Institution/United States Geological Survey Weekly Volcanic Activity Report covering 7-13 March 2012. It is provided for information only, and is based on but not a substitute for the full report, which comes with its own criteria and disclaimers. The map base is derived from the Smithsonian Institution/USGS/US Naval Research Laboratory This Dynamic Planet website.

For all our coverage of the SI/USGS Weekly Volcanic Activity Reports: Weekly Volcanic Activity Reports « The Volcanism Blog.

Yesterday afternoon at approximately 2:55 pm AKDT (22:55 UTC), AVO infrasound and seismic networks detected a small explosion at Cleveland. Clouds prevented a clear view of the volcano at the time of the explosion, however, ash was not observed rising through the cloud deck suggesting relatively minor ash emission.

The Volcano Alert Level for Cleveland remains at Watch, the Aviation Colour Code at Orange. The same report notes that seismicity remains elevated at Iliamna volcano (which remains at Yellow/Advisory).

News
Cleveland volcano explodes for the third time – alaskapublic.org, 14 March 2012

Information
Global Volcanism Program: Cleveland – summary information for Cleveland (1101-24-)
Global Volcanism Program: Iliamna – summary information for Iliamna (1103-02-)
AVO Cleveland Activity Page – information on current activity at Cleveland
AVO Iliamna Activity Page – information on current activity at Iliamna
Alaska Volcano Observatory – AVO main page

‘Papers relating to the recent volcanic eruptions in Santorin’, Proceedings of the Royal Geographical Society of London, vol. 10, no. 3 (12 March 1866), pp. 119-20. Dr Johann Friedrich Julius Schmidt was Director of the Royal Observatory at Athens from 1858 to 1884, and had travelled with his colleagues on the Aphroessa to Santorini (called here ‘Santorin’) to observe and study the 1866 eruption.

The Daily Volcano Quote: from Monday to Friday, a new eruption of volcanic verbiage each day.

Santorini, then, is very much an active volcano, and there are currently indications that it is becoming restless once again. A team led by Dr Andrew Newman of Georgia Tech has been monitoring Santorini through a dense network of GPS stations since 2006. Over the past year, since January 2011, these instruments have detected a reawakening of the volcano. Newman’s team has published their observations in Geophysical Research Letters (papers in press). To quote from the abstract:

After approximately 60 years of seismic quiescence within Santorini caldera, in January 2011 the volcano reawakened with a significant seismic swarm and rapidly expanding radial deformation. The deformation is imaged by a dense network of 19 survey and 5 continuous GPS stations, showing that as of 21 January 2012, the volcano has extended laterally from a point inside the northern segment of the caldera by about 140 mm and is expanding at 180 mm/yr. A series of spherical source models show the source is not migrating significantly, but remains about 4 km depth and has expanded by 14 million m3 since inflation began.

An injection of fresh magma is clearly going on at depth. This may not produce eruptive activity at the surface at all (Professor Newman points out that other calderas around the world have shown comparable activity without erupting), but Santorini, a volcano with the potential to be very dangerous, is evidently getting restless once again.

• A. V. V. Newman, S. Stiros, L. Feng, P. Psimoulis, F. Moschas, V. Saltogianni, Y. Jiang, C. Papazachos, D. G. Panagiotopoulos, E. Karagianni, & D. Vamvakaris, ‘Recent geodetic unrest at Santorini Caldera, Greece’, Geophysical Research Letters, doi:10.1029/2012GL051286, in press (accepted 6 March 2012). [abstract]

News
Santorini: the ground is moving again in paradise – Georgia Tech news release, 13 March 2012 (duly recycled at ScienceDaily, esciencenews and probably elsewhere too)
Volcanic island of Santorini shows activity – Greek Reporter, 13 March 2012
Volcanic activity detected on Greek island – TG Daily, 14 March 2012
Volcano on scenic Greek island getting a little restless – msnbc.com, 14 March 2012
Greek volcano reawakens – ScienceNews, 14 March 2012

Information
Global Volcanism Program: Santorini – GVP information for Santorini (0102-04=)
ISMOSAV – Institute for the Study and Monitoring of the Santorini Volcano
Santorini Decade Volcano – Santorini profile from the Decade Volcanoes project

[H/T: VolcanoDiscovery.]

Information
Global Volcanism Program: Ijen – summary information for Ijen (0603-35=)

Over the past couple of weeks Sakura-jima has shown an increase in the level of its activity, with ash explosions increasing in size and frequency. Yesterday there was a sizeable explosion which the Japan Meteorological Agency classed as the most powerful since 2009 (‘Foot-wide rocks were expulsed over a mile away’ reports the Daily Telegraph, incoherent with excitement), and today the activity has continued with violent explosions, lava fountaining, and pyroclastic material being ‘expulsed’ up to 2 km altitude.

News
Volcano erupts violently in Japan – Daily Telegraph, 13 March 2012 (video)
Moment volcano erupted in Japan – BBC News, 13 March 2012 (video)

Information
Global Volcanism Program: Sakura-jima – summary information for Sakura-jima (0802-08=)